Production of lactic and acetic acids



i atented May 3, 1932 PATENT OFFICE WILLIAM H. PETERSON AND EDWIN B. FRED,

OF MADISON, WISCONSIN, ASSIGNORS TO WISCONSIN ALUMNI RESEARCH FOUNDATION, A CORPORATION PRODUCTION OF LACTIC AND ACETIC ACIDS No Drawing. Original application filed August 17, 1927, Serial No. 218,702. Divided and this application filed May 23, 1929.

The present invention relates to the production of lactic and acetic acids from hitherto unused and waste materials, or from other materials by a heretofore unisolated microorganism, and is a division of our application Serial No. 213,702, filed August 17, 1927 which has matured into Patent No. 1,7 23,298.

Lactic and acetic acids, as heretofore produced, have been obtained exclusively from heXose or heXose' yielding materials such as glucose, maltose and starch, but not from materials yielding both heXoses and pentoses such as wood, straw and corncobs. This process has for one of its purposes the fermentation of both hexoses and pentoses simultaneously by the hereinafter described bacteria, and thus furnishing a new and valuable source of lactic and acetic acids, the lactic acid being the one of principal importance.

Another purpose is to provide a process for the fermentation of either hexoses or pentoses by the said bacteria to produce lactic and acetic acids. The process is the same when used upon materials containing and pentoses, and we, therefore, for convenience, describe it in respect only to a material containing both heXoses and pentoses.

The mixture of hexoses and pentoses may be obtained from wood, sawdust, straw, corncobs, corn stover, cotton seed hulls or other equivalent plant materials by hydrolysis with dilute acidsunder suitable conditions of temperature and pressure, e. g., sulphuric acid of 2.5 per cent. strength at a temperature of one hundred pounds steam pressure for fifteen minutes. The unhydrolyzed residue is removed by filtering and leaching with water which gives a dark colored liquid and contains the hexoses and pentoses. This liquid may be diluted or concentrated to give a concentration of sugars most suitable for fermentation, from two to four per cent.

To bring about this fermentation the acid solution is neutralized with milk of lime or calcium carbonate and suitable nitrogenous nutrients such as malt sprouts, tankage or other protein containing material are added. An excess of calcium carbonate or other alka- 50 line reagent is added'to neutralize the lactic hexoses or pentoses or a mixture of hexoses Serial No. 365,557.

and acetic acids as they are formed by the bacteria. The medium is then inoculated with a suitable culture of the bacteria.

An excellent method of inoculation is to add an inoculum equivalent to about one per cent. of the volume of medium to be fermented. The inoculum may be obtained by seedmg a small quantity of the same medium with the bacteria and allowing them to grow for twenty-four hours before using.

In this manner, a vigorous and active inoculum is built up which when transferred to the larger volume of medium produces a rapid fermentation and converts the heXoses and pentoses almost quantitatively to lactic and acetic acids. After a few days the fermentation is completed and the lactic and acetic acids may be obtained by several Wellknown methods. The details of the fermentation process may be varied considerably With respect to concentration of sugars and nutrients, duration of the fermentation and temperature employed.

The newly discovered micro-organism which we employ may be isolated from fermenting plant material such as silage or sauerkraut by plating juice from such materials and picking isolated colonies according to well known bacteriological methods. This microorganism may be identified in accordance with the descriptive chart of the Society of American Bacteriologists, as follows:

Monrnonocr reaction,

C. age,

of di- Staining reactions:

1 day, Gram positive. Technic used, standard methods.

CULTURAL CHARACTERISTICS Agar stab Medium, glucose yeast-water agar. Incubation temperature, 28 C. Age, 24 hours. 7 Growth, uniform. Line of puncture, papillate. Optical character, opaque. Medium, unchanged.

Ligaiil medium:

Glucose yeast-Water.

. Surface growth, none.

Olouding, moderate. Odor, absent. q Sediment, slight and flocculent.

' PHYSIOLOGY arabinose, mannose, ga-

fructose, lactose, maltose, sucrose, raflinose, salicin, amygdalin, manitol, melezitose+slightly,; dextrin-slightly, alpha-methyl glucosideslightly, sodium lactateslightly. Special tests: I

Fermentation products. I I From pentoses, acetic acid and lactic acid.

. N 0 gas.

From hexoses,'lactic acid. No gas, no ethyl alcohol.

.teria. I 3. The process which co pentoses bacteria have culiar and novel feature of these bacteria is that they ferment both groups of sugars.

e claim: 1. The process of fermenting pentoses with the herein described bacteria.

2. Theprocess of producing acetic acid by V the fermentation ofa liquid containing pentoses by means of the herein described bacnprisessubjecting to the action of the herein-described and allowing the fermentation to proceed until substantially all of the pentoses d bee'n'converted into acetic and lactic aci s.

. In witness that we claim the foregoing, we

- have hereunto subscribed our names this 14th day of May, 1929. I

* WILLIAM H. PETERSON. v EDWIN B. FRED. i

In place of the dilute'sirupobtained by the I hydrolysisof wood, sawdust, corncobs, straw, etc., molasses or other cheap saccharine mate rials containing both hexoses and pentoses may be employed. It is not to be understood, however, that the micro-organisms which we have described require both hexoses and pentoses for their action. Either of these groups of carbohydrates maybe fermented separately or combined. The pe- 

